Adjustable spark-plug.



J. S. PALMER.

ADJUSTABLE SPARK PLUG.

APPLICATION 211.111) JAN. 1a, 1908.

Patented May 3, 1910.

Svwewfoz Witnuaeo umrn w s PATENT "carries.

JEFFERSON S. PALMER, OF CLARK, SOUTH- DAKOTA.

ADJUSTABLE SPARK-PLUG.

To all whom it may concern:

Be it known that I, JEFFERSON S. PALMER, a citizen of the United States,residing at Clark, in the county of Clark and State of South Dakota,have invented certain new and useful Improvements in AdjustableSpark-Plugs; and I do hereby declare the following to be a full, clear,and exact de scription of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings,

' and to the letters of reference marked thereon, which form a part ofthis specification.

This invention relates to new and useful improvements in adjustablespark plugs, the object in View being to generally improve upon andrender more eflicient devices of this nature.

The invention consists in various details of-construction, combinationsand arrangements of parts-which will be hereinafter fully described andthen specifically defined in the appended claim.-

My invention is illustrated in the accompanying drawings, in whichFigure 1 is a perspective view of the plug, showlng the adjustable wireterminal attached thereto. Fig. 2 is a longitudinal section centrallythrough the plug. Fig. 3 is a detailed view of the adjustable terminal,and Fig. 4 is a detailed view of the adjustable jump spark screw.

Reference now being had to the details of the drawings by letter, Adesignates a plug casing having threaded circumference designed toengage the threaded aperture in the cylinder of an engine, and B is alock nut having a threaded circumference designed to engage the threadson the inner wall of the casing.

C designates a porcelain insulator which is centrally apertured toreceive the firing pin D. Said pin has a threaded end D, uponwhich ismounted a nut E. Mounted about said insulator is packing ring G, madepreferably of copper, and against which said lock nut B is adapted tobear, thereby preventing any leakage by the lock nut. Underneath thering G is a packing Gr, preferably of asbestoes to insure an air tightjoint. A loop F s connected to the inner end of the cas ng at pointsdiametrically opposite and said loop carries a jump spark screw Hmounted in a threaded aperture in said loop. Said screw has a notchSpecification of Letters Patent. 7

Patented ma a, rare.

Application filed January 16, 1908. Serial No. 411,182.

in its inner end forming two points H. By the provision of said loopmounted as shown, two currents of electricity are designed to flow tothe jump spark screw, one from either side of the plug, both currentsjoining at the screw H and causing the positive current flowing throughthe pin D to jump to the two points of the screw completing the circuit.

An adjustable wire terminal, designated by letter N, is provided havinga slot N therein adapted to receive the threaded por-' tion of saidfiring pin and held in an adjust ed position thereon by the nut upon thethreaded end of the firing in., Said terminal has a laterally pro ectinglug N carrying a screw 0 upon which a threaded nut R ismounted, designedto cooperate with a nut S to securely hold a terminal wire. By thisadjustable arrangement, it will be noted that, by sliding the terminalback and forth, the wire may be tightened and loosenedas may-be desiredand also allowed to revolve about the firing pin.

By the construction of a sparking plug as shown and described, a simpleand efficient device is afforded which will work under all conditions ina gas engine and affording two currents flowing through the plug,thereby doubling the efiiciency of the plug, all leakage about theporcelain being prevented and the latter so constructed as to beadjustable in order to suit various gas mixtures and also adjustable fordifi'erent voltage. By screwing in the jump spark screw and lesseningthe gap between the H, thereby same and the firing pin, the plug willWork on exceedinglyweak batteries with satisfactory results and, byincreasing the spark gap, the plug maybe adjusted to a very strongvoltage and give perfect results under various conditions. Owing to theenlarged air chamber in the bottom of the plug, the suction from theexhaust will clean out the air chamber at each explosion and a plug willbe soot-proof. Uwing to the-adjustabilityof the terminal, the wires maybe adjusted in any positions and may be readily removed by simplyloosening the lock nut.

' What I claim is A hollow sparking plug comprising a shell with anenlarged chambered portion therein terminating in an inclined shoulder,the interior of said shell being contracted beyond the shoulder the oneend-of the shell having a semi-cylindrical bridge loop, a screw fittedin an aperture therein and having terminal points, an insulating plugprovided with an enlarged chambered portion adjacent to its inner endterminating in a shoulder and provided with a beading upon itscircumference a short distance from its inner end, said beading adaptedto rest upon the inclined shoulder in the shell with the portion of theplug beyond said beading extending into the contracted portion of theopening beyond said chambered part, a headed screw passing through alongitudinal aperture in said plug and having its head seated upon saidshoulder at the inner end of said chambered portion formed in the innerend of the plug, a contracted pin extension upon the head of said screwand forming a terminal, a cap fitted over the outer end of the plug andthrough which said screw passes, a nut upon the threaded portion of thescrew, and a gland about said plug and engaging said shell, as shown anddescribed.

In testimony whereof I hereunto affix my signature in the presence oftwo witnesses. 25

VVELLINGTON K. Moonn, LINFORD J. l/VILLTAMS.

